1. Field of the Invention
The present invention relates to a blind apparatus which is suspended on a wall or the like of a room and which can be hoisted up or down arbitrarily. More particularly, the present invention relates to a horizontal type blind in which a plurality of slats are supported horizontally by means of a ladder cord hung from a head box at a distance between respective upper and lower slats and in which lifting cords fit to a bottom rail disposed at the bottommost of the slats are introduced upward through the slats and then introduced into the head box, the lifting cords being further introduced within the head box horizontally toward one end of the head box, and in which the slats are lifted up or down by pulling or loosening the lifting cords and turned by moving up or down vertical cords located before and after the aforementioned ladder cord.
2. Description of the Related Art
Horizontal type blind apparatuses of the aforementioned type have been widely used. The horizontal type blinds enable the user to lift up or down the slats and adjust the slat angle easily. It is also possible to suspend the slats at a desired height by fastening the lifting cords at a desired position by means of a stopper device.
Recently, a new type blind apparatus has been proposed. According to the proposed invention, a rotating operation rod for rotating the slats is disposed near one end of the head box, and one end of the lifting cord is passed through the rotating operation rod and introduced downward from the bottom thereof. The slats are rotated by means of the rotating operation rod and lifted up or down by means of the lifting cords.
An example of the invention has been disclosed in Japanese Utility Model Laid-Open No. 61-102797.
In the horizontal type blind apparatus of this type, a stopper device which holds the motion of the lifting cords is incorporated near one end of the head box in order to fasten the lifting cords at a desired position.
In the prior art, the following stopper devices for the blind apparatus have been proposed. According to Japanese Patent Laid-Open No. 58-27399, lifting cords which are capable of lifting up or down the slats are inserted through a hollow operation rod which is capable of changing the inclination angle of the slats, and a grip disposed at the lower end of the operation rod is provided with a locking metal piece which is capable of locking the lifting up or down of the lifting cords.
However, the conventional stopper devices for such blind apparatus have the following problems. That is, because the locking metal piece is provided on the grip, an operating load is applied to the operation rod when the slats are lifted up or down. Thus, it is necessary to provide an operation rod having a large diameter in order to obtain sufficient strength, thus the size of the operation unit increases.
To solve the aforementioned problem, according to Japanese Utility Model Laid-Open No. 3-35035, in a differential drum which is capable of transmitting the rotation of the operating handle disposed in the head box to a rotation shaft, a stopper device is incorporated which has a conical portion having a U-shaped cross section capable of holding the lifting up or down of by nipping the lifting cords in cooperation with the tapered portion of the differential drum, and the lifting cords introduced from the head box are inserted through the hollow operating handle and then led out of the bottom of the operating handle. Additionally, one end of a stopper releasing cord which is capable of releasing the fastening of the lifting cords is connected to the stopper. Regarding the connection of the stopper releasing cord to the stopper, one end of the stopper releasing cord is introduced from the bottom of the stopper into the conical portion and a knot is formed in order to contain the knot of the stopper releasing cord within the conical portion. The other end of the stopper releasing cord is inserted through the operating handle and introduced out from the bottom end of the operating handle. When it is desirable to lift up the slats, the lifting cords are pulled downward to release the stopper. When it is desirable to let down the slats, the stopper is released by pulling the stopper releasing cord downward.
However, because the differential drum includes the function for transmitting the rotation of the operating handle to the rotation shaft as well as a stopper, the internal space of the differential drum is increased and the size of the differential drum is increased. Thus, the play of the lifting cord is increased. Additionally, because the differential drum and the stopper rotate integrally or relatively to each other, the lifting cords are likely to be twined. Further, because the stopper cannot be assembled beforehand because of the construction reasons, the workability of the assembly is low.
Still further, because the knot formed in the stopper releasing cord is contained in the conical portion of the stopper, the diameter of the conical portion must be increased. Thus, the conical portion must be formed so as to have a U-shaped cross section. Thus, when the lifting cords are nipped between the stopper and the tapered portion, the lifting cords slip so that the cord cannot be nipped firmly. That is, there is a possibility that the stopper may not be activated. The aforementioned problem is the first problem of the blind apparatus of the prior art.
As a conventional blind apparatus for operating the blind apparatus of the aforementioned type, the following invention has been proposed. For example, according to Japanese Utility Model Laid-Open No. 3-35035, a stopper device which is capable of locking the lifting up or down of the lifting cords is provided within the head box. The lifting cords are inserted through the operation handle and connected to different positions of the lifting operation knob which is rotatable with the operation handle, so that the slats can be lifted up or down. The bottom end of the releasing cord which is capable of operating the stopper mechanism is inserted through the operation handle and connected to the releasing operation knob which is rotatable with the operation handle, so that the slats can be lifted up or down. When the releasing operation knob is pulled down, the stopper mechanism is released, so that the slats descend.
However, the aforementioned conventional blind apparatus has the following problems. That is, when the slats are rotated, if the operation handle is turned, the lifting operation knob and the releasing operation knob rotate integrally therewith. Thus, the lifting cords and the releasing cord are twined within the operation handle.
Japanese Utility Model Laid-Open No. 57-99094 has disclosed an example in which the lifting cords are prevented from being twined. Namely, the bottom ends of the lifting cords which droop from the stopper mechanism provided at the bottom of the rotating operation rod are inserted through respective insertion holes provided on the knob having the same number of insertion holes as the number of the lifting cords and then connected with each other. However, this system prevents the lifting cords introduced from the bottom end of the rotating operation rod from being twined, because the stopper mechanism is provided at the bottom end of the rotating operation rod. Thus, even if this system is utilized in an apparatus which includes a stopper mechanism within the head box, it is not possible to prevent the lifting cords from being twined within the operation handle. The aforementioned matter is the second problem of the conventional blind apparatus.
As another example of conventional blind apparatus, the following apparatus is available. For example, according to Japanese Patent Laid-Open No. 60-113823, a universal joint is utilized. In this construction, bifurcated pieces are provided on each end of a hollow driving shaft and a hollow driven shaft and both bifurcated pieces are pivotally connected by a hollow connecting piece. Both bifurcated pieces and the connecting piece are pivotally connected by fitting a protrusion of each connecting point of the connecting piece into a receiving hole formed at each connecting point of each bifurcated piece. Both bifurcated pieces and the connecting piece are pivotally connected so that the center lines of the aforementioned shafts and a line connecting the respective connecting points of the connecting piece and the bifurcated pieces pass through the center of the connecting piece.
However, the aforementioned conventional blind apparatus has the following problem. That is, because the driving shaft, the driven shaft, the bifurcated piece and the connecting piece are hollow, the bifurcated pieces are bent by a downward load applied to the operation rod, so that the protrusions of the connecting piece are disengaged from the receiving holes of the bifurcated pieces.
According to another example of conventional apparatus, a washer is attached to the tip of the protrusion of the connecting piece in order to prevent the protrusions of the connecting pieces from being disengaged from the receiving holes of the bifurcated pieces. However, because a washer must be attached to every protrusion, the work necessary for this treatment is very troublesome.
These points are the third problem of the conventional blind apparatus.
In the aforementioned known blind apparatus, the device which inclines all the slats all at once to adjust the light shielding is called a tilter.
The tilter of the conventional blind apparatus contains, for example, a worm gear for transmitting the rotation of the rotating operation rod to a transmission shaft and a worm wheel and some types of the apparatus contain the tilter which is provided within the head box located at the top end of the rotating operation rod. The lifting cord is inserted through the rotating operation rod.
However, the tilter of the conventional blind apparatus has the following problem. Namely, when the slats are rotated by rotating the rotating operation rod, if the slats are lifted halfway and the rotating operation rod with the lifting cord introduced from the bottom of the rotating operation rod being hung on a cord hanger is rotated, the lifting cord within the rotating operation rod is twined. For this reason, a repellant force which tries to untwine the lifting cord is caused so that the rotating shaft rotates. Thus, it is not possible to maintain the slats in a desired condition.
The smaller the gear ratio between the worm gear and the worm wheel is, the more excellent rotation transmission efficiency the tilter has. However, the tilter utilizes braking force which occurs between the worm gear and the worm wheel in order to prevent the rotation shaft from being forced to rotate due to the aforementioned repellant force and an external force applied to the slat. Thus, the actual gear ratio is set to a relatively high value. For this reason, it is necessary to rotate the rotating operation rod by five-six turns in order to tilt the slats by 180 degrees.
Although the aforementioned problem can be solved if the worm gear and the worm wheel are made of material which is difficult to slip, if they are made of such material, it is not possible to secure a smooth rotation when the rotating operation rod is rotated, so that the gear ratio increases. This is the fourth problem of the conventional blind apparatus.
As the rotating operation rod of the conventional blind apparatus, the following apparatus has been proposed. For example, according to Japanese Utility Model Laid-Open No. 56-70091, a safety device having a substantially T-shaped cross section, which has a disk shaped head at one end of the thread portion is fixed to the rotating operation rod and the grip and the lifting cords are wound around the safety devices.
According to Japanese Patent Laid-Open No. 61-56383, T-shaped hooks protrude at two positions which are located at a predetermined distance along the length of the rotating operation rod and the lifting cords are wound around the hooks.
However, the rotation operation bar of the conventional blind apparatus has the following problem. That is, in the apparatuses disclosed in Japanese Utility Model Laid-Open No. 56-70091 and Japanese Patent Laid-Open No. 61-56383, the lifting cords are only wound around the hook having a substantially T-shaped cross section, which protrudes sideways from the rotating operation rod or the grip. Thus, when the slats are blown by the wind or the rotating operation rod is rotated with the condition in which the blind apparatus is descended halfway and the lifting cord is wound around the hook, the lifting cord is unwound from the hook.
Generally, a pair of lifting cords are disposed near both ends of the blind apparatus. However, it is necessary to provide a large size blind apparatus with a further or more lifting cords which are located in the center of or near the center thereof.
In a blind apparatus which utilizes at least three or more lifting cords, as compared with lifting cords which pass near both ends of the slats, a larger load is applied to lifting cords which pass in the center of the slats by a bottom rail and slats.
Because the lifting cord stopper device which fastens the lifting cords to stop the blind fastens all the lifting cords with equal force, the lifting cords which are applied with the largest load and which pass in the center of the slats are likely to slip even when the stopper fastens the lifting cords, so that the lifting cord stopper device cannot fasten the lifting cords which pass near the center of the slats. As a result, when the slats are descended halfway, the center portions of the slats and the bottom rail droop so that the level condition of the slats and the bottom rail cannot be maintained.
This point is also one of the problems which must be solved about the blind apparatus.
The blind apparatuses of the aforementioned types are fixed to a wall or the like of a room through a bracket.
As a construction which utilizes such fixing, the following types are known.
In the head box of conventional blind apparatus, the respective edges of both sides are bent inward and the head box is mounted on brackets by hooking the edges of both sides on hooking pieces of the brackets. The head box contains a rotating drum to which one end of the ladder cord supporting the slats is connected so that the ladder cord can be wound or rewound, a tilter which transmits the rotation of the rotating operation rod to the rotating drum and mechanical parts such as a stopper capable of holding the motion of the lifting cords for lifting up or down the slats. When the respective components are fixed to the head box, the top portions thereof are in contact with the aforementioned edges of the head box.
However, the aforementioned conventional blind apparatuses have the following problem. Because the mechanical parts are in contact with some locations of the edge portions of the head box, the brackets must be mounted at positions which no mechanical parts are fit to. Thus, when brackets are mounted on a window frame or the like, it is necessary to set the mounting positions of the brackets so as to avoid an interference between the mechanical parts and the brackets.
Although, in a blind apparatus in which both edge portions of the head box are bent outward, the brackets can be attached freely to any positions of the head box without taking into account the positions of the mechanical parts, the edge portions of the head box protrude outward, so that the width of the bracket must be increased. Thus, the appearance of the head box is deteriorated. This is also one of the problems which must be solved in conventional blind apparatuses.
Still another type of conventional blind bracket is disclosed in Japanese Utility Model No. 60-22237. The blind bracket disclosed therein comprises a substantially L-shaped supporting frame fit to a window frame and an engaging member detachable from the supporting frame. In the supporting frame, a cut-out dented portion is formed at the bottom of the beginning end of its level portion and a upward facing dented portion is formed at the front end of the level portion. The engaging member is supported by a supporting frame so that the engaging member is movable back and forth. In the engaging member, an engaging protrusion is formed at a position which corresponds to the cut-out dented portion when the engaging member is inserted into the supporting frame completely, and a locking piece and a locking tongue are formed at a position which corresponds to the engaging dented portion.
When the engaging member is inserted into the supporting frame completely, the top edge of one side of the box (otherwise called head box) is nipped between the cut-out dented portion and the engaging protrusion and fixed. The top edge of the other side is nipped between the locking tongue and the locking piece, the locking tongue and the locking piece sliding beyond the top edge thereof, in order to hold the right/left movement of the head box. Additionally, the top edge of the other side is nipped between the locking tongue and the engaging dented portion in order to restrict the up/down motion of the head box, thereby fixing the head box to the brackets. By pulling the engaging member from the supporting frame by a predetermined distance, the engaging protrusion which supports the bottom of the top edge of one side of the head box is moved so that the top edge is released from being supported. The locking tongue goes beyond the top edge of the other side, so that seizing of the top edge in the right/left direction and in the upward direction is eliminated. Thus, the head box can be removed from the bracket.
However, as for the aforementioned conventional bracket for the blind apparatus, if the engaging member is pulled out from the supporting frame, the top edge of one side of the head box becomes unsupported, so that the head box drops from the brackets. Thus, to adjust the right/left position of the blind apparatus after the head box is mounted to the supporting frame, it is necessary to support the head box by hand or the like to stop the head box from dropping. For this reason, according to this invention, it is not possible to adjust the right/left position of the blind apparatus easily.
Depending on a case, it is requested to mount the blind apparatus of the aforementioned type in a narrow space, for example, between double sashes or between a sash and a Japanese sliding paper door. In such a case, because the distance between the inside and outside sashes is small, it is desirable to reduce the back-and-forth dimension of the head box and further it is desirable that the bracket does not protrude.
The bracket which can meet such a demand comprises a supporting member mounted on the top surface of the top mounting space and a locking member mounted horizontally rotatably with respect to the Supporting member. A locking portion which is locked on a locking protruded edge formed inside of the top edge of the groove type head box is formed on the locking member. By rotating the locking member by means of an operation lever formed integrally with the locking member, the head box is locked or released.
Japanese Patent Laid-Open No. 40-34054 has disclosed the following type of the device for fixing a blind apparatus or a curtain supporting frame. This device comprises a supporting frame in which protruding edges which direct inward are formed at the top ends on both side walls and a groove is formed between the protruding edges and a fixing device in which a circular rise-up entering the groove of the supporting frame is formed on both sides of a substrate, in which a protruding edge engaging with the bottom faces of both protruding edges of the supporting frame is formed on the ends, in which handles are provided in succession between both protruding edges and in which a nail hole is formed in the center thereof. The fixing device is nailed on the upper beam of a partition of a room, window or the like so that the device is freely rotatable. The bent pieces of the supporting frame are hooked on both protruding edges.
Japanese Patent Laid-Open No. 63-106893 has disclosed a blind apparatus fixing metal piece in which engaging edges are formed by bending inward the top edges of the groove type frame and the engaging edges of the frame are engaged therewith by rotating the lever to fix the frame, the fixing metal piece being constructed so that the engaging member which is engaged between the bottom of the frame and the engaging edge is supported so as to be rotatable and that a lever for rotating the engaging member is connected to the engaging member.
Further, Japanese Patent Laid-Open No. 63-173497 has disclosed a blind fixing metal piece in which engaging edges are formed by bending inward the top edges of a groove type frame and the engaging edges of the frame are engaged therewith by rotating the operation lever, the fixing metal piece being constructed so that a shaft from which the operation lever originates is supported on one end of the supporting member so as to be rotatable, the supporting member being provided with a locking portion for supporting one engaging edge of the frame, one side of the shaft being provided with a locking groove which is locked on the other engaging edge according to the rotation of the operation lever.
However, if a blind apparatus is mounted in a narrow space, for example, between a sash outside and a Japanese sliding paper door inside by means of the aforementioned bracket, the protrusion dimension of the front end of the operation lever is so large that a force for releasing engagement between the bracket and the head box is applied to the front end of the operation lever. For example, if a sliding paper door is opened, the operation lever is turned in the direction in which the head box is released, so that the blind may drop. This is also one of the problems which must be solved about conventional blind apparatus.